Yakhchāl

[1] The structure typically had a domed shape above ground, a subterranean storage space, shade walls, and ice pools.

[2] The ice created nearby and stored in yakhchāls is used throughout the year especially during hot summer days, for various purposes, including preservation of food,[1] to chill treats, or making traditional Persian desserts like faloodeh and sorbets.

[3] Although many have deteriorated over the years due to widespread commercial refrigeration technology, some interest in them has been revived as a source of inspiration in low-energy housing design and sustainable architecture.

These still have their cone-shaped, eighteen meter high building, massive insulation, and continuous cooling waters that spiral down its side and keep the ice frozen throughout the summer.

Their design is generally split into three areas:[2] However, they varied greatly, as some used all three components, whereas others were simply a large shade wall over a thin pool.

At the same time, the building allows cold air to pour in from entries at the structure's base and descend to the lowest part of the yakhchāl: large underground spaces up to 5,000 m3 (180,000 cu ft) in volume.

This mortar is composed of sand, clay, egg whites, lime, goat hair, and ash in specific proportions, is resistant to heat transfer and is thought to be completely water-impenetrable.

[2] Water is often channeled from a qanat to a yakhchāl, which is used to fill the provisioning pools or used to power the evaporative cooling throughout the ice house.